Pre-operative enhanced magnetic resonance imaging combined with clinical features predict early recurrence of hepatocellular carcinoma after radical resection

BACKGROUND

Indentifying predictive factors for postoperative recurrence of hepatocellular carcinoma (HCC) has great significance for patient prognosis.

AIM

To explore the value of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) enhanced magnetic resonance imaging (MRI) combined with clinical features in predicting early recurrence of HCC after resection.

METHODS

A total of 161 patients with pathologically confirmed HCC were enrolled. The patients were divided into early recurrence and non-early recurrence group based on the follow-up results. The clinical, laboratory, pathological results and Gd-EOB-DTPA enhanced MRI imaging features were analyzed.

RESULTS

Of 161 patients, 73 had early recurrence and 88 were had non-early recurrence. Univariate analysis showed that patient age, gender, serum alpha-fetoprotein level, the Barcelona Clinic Liver Cancer stage, China liver cancer (CNLC) stage, microvascular invasion (MVI), pathological satellite focus, tumor size, tumor number, tumor boundary, tumor capsule, intratumoral necrosis, portal vein tumor thrombus, large vessel invasion, nonperipheral washout, peritumoral enhancement, hepatobiliary phase (HBP)/tumor signal intensity (SI)/peritumoral SI, HBP peritumoral low signal and peritumoral delay enhancement were significantly associated with early recurrence of HCC after operation. Multivariate logistic regression analysis showed that patient age, MVI, CNLC stage, tumor boundary and large vessel invasion were independent predictive factors. External data validation indicated that the area under the curve of the combined predictors was 0.861, suggesting that multivariate logistic regression was a reasonable predictive model for early recurrence of HCC.

CONCLUSION

Gd-EOB-DTPA enhanced MRI combined with clinical features would help predicting the early recurrence of HCC after operation.

Quantitative information from gadobenate dimeglumine-enhanced MRI can predict proliferative subtype of solitary hepatocellular carcinoma: a multicenter retrospective study

OBJECTIVES

To investigate the value of quantitative parameters derived from gadobenate dimeglumine-enhanced magnetic resonance imaging (MRI) for predicting molecular subtype of hepatocellular carcinoma (HCC) and overall survival.

METHODS

This multicenter retrospective study included 218 solitary HCC patients who underwent gadobenate dimeglumine-enhanced MRI. All HCC lesions were resected and pathologically confirmed. The lesion-to-liver contrast enhancement ratio (LLCER) and lesion-to-liver contrast (LLC) were measured in the hepatobiliary phase. Potential risk factors for proliferative HCC were assessed by logistic regression. The ability of LLCER and LLC to predict proliferative HCC was assessed by the receiver operating characteristic (ROC) curve. Prognostic factors were evaluated using the Cox proportional hazards regression model for survival outcomes.

RESULTS

LLCER was an independent predictor of proliferative HCC (odds ratio, 0.015; 95% confidence interval [CI], 0.008-0.022; p < 0.001). The area under the ROC curve was 0.812 (95% CI, 0.748-0.877), higher than that of LLC, alpha-fetoprotein > 100 ng/ml, satellite nodules, and rim arterial phase hyperenhancement (all p ≤ 0.001). HCC patients with LLCER < -4.59% had a significantly higher incidence of proliferative HCC than those with the LLCER ≥ -4.59%. During the follow-up period, LLCER was an independent predictor of overall survival (hazard ratio, 0.070; 95% CI, 0.015-0.324; p = 0.001) in HCC patients.

CONCLUSIONS

Gadobenate dimeglumine-enhanced quantitative parameter in the hepatobiliary phase can predict the proliferative subtype of solitary HCC with a moderately high accuracy.

CLINICAL RELEVANCE STATEMENT

Quantitative information from gadobenate dimeglumine-enhanced MRI can provide crucial information on hepatocellular carcinoma subtypes. It might be valuable to design novel therapeutic strategies, such as targeted therapies or immunotherapy.

KEY POINTS

• The lesion-to-liver contrast enhancement ratio (LLCER) is an independent predictor of proliferative hepatocellular carcinoma (HCC). • The ability of LLCER to predict proliferative HCC outperformed lesion-to-liver contrast, alpha-fetoprotein > 100 ng/ml, satellite nodules, and rim arterial phase hyperenhancement. • HCC patients with LLCER < -4.59% had a significantly higher incidence of proliferative HCC than those with the LLCER ≥ -4.59%.

A case of focal nodular hyperplasia-like lesion presenting unusual signal intensity on the hepatobiliary phase of gadoxetic acid-enhanced magnetic resonance image

Focal nodular hyperplasia (FNH) or FNH-like lesions of the liver are benign lesions that can be mostly diagnosed by hepatobiliary phase gadoxetic acid-enhanced magnetic resonance imaging (MRI). Accurate imaging diagnosis is based on the fact that most FNHs or FNH-like lesions show characteristic hyper- or isointensity on hepatobiliary phase images. We report a case of an FNH-like lesion in a 73-year-old woman that mimicked a malignant tumor. Dynamic contrast-enhanced computed tomography (CT) and MRI using gadoxetic-acid revealed an ill-defined nodule showing early enhancement in the arterial phase and gradual and prolonged enhancement in the portal and equilibrium/transitional phases. Hepatobiliary phase imaging revealed inhomogeneous hypointensity, accompanied by a slightly isointense area compared to the background liver. Angiography-assisted CT showed a portal perfusion defect of the nodule, inhomogeneous arterial blood supply in the early phase, and less internal enhancement in the late phase, accompanied by irregularly shaped peritumoral enhancement. No central stellate scar was identified in any of the images. Imaging findings could not exclude the possibility of hepatocellular carcinoma, but the nodule was pathologically diagnosed as an FNH-like lesion by partial hepatectomy. In the present case, an unusual inhomogeneous hypointensity on hepatobiliary phase imaging made it difficult to diagnose the FNH-like lesions.

Diagnostic performance of abbreviated gadoxetic acid-enhanced magnetic resonance protocols with contrast-enhanced computed tomography for detection of colorectal liver metastases

BACKGROUND

Although contrast-enhanced magnetic resonance imaging (MRI) using gadoxetic acid has been shown to have higher accuracy, sensitivity, and specificity for the detection and characterization of hepatic metastases compared with other modalities, the long examination time would limit the broad indication. Several abbreviated enhanced MRI (Ab-MRI) protocols without dynamic phases have been proposed to achieve equivalent diagnostic performance for the detection of colorectal liver metastases. However, an optimal protocol has not been established, and no studies have assessed the diagnostic performance of Ab-MRI combined with contrast-enhanced computed tomography (CE-CT), which is the preoperative imaging of colorectal cancer staging in clinical settings, to determine the best therapeutic strategy.

AIM

To compare the diagnostic performance of two kinds of Ab-MRI protocol with the standard MRI protocol and a combination of the Ab-MRI protocol and CE-CT for the detection of colorectal liver metastases.

METHODS

Study participants comprised 87 patients (51 males, 36 females; mean age, 67.2 ± 10.8 years) who had undergone gadoxetic acid-enhanced MRI and CE-CT during the initial work-up for colorectal cancer from 2010 to 2021. Each exam was independently reviewed by two readers in three reading sessions: (1) Only single-shot fast spin echo (FSE) T2-weighted or fat-suppressed-FSE-T2-weighted, diffusion-weighted, and hepatobiliary-phase images (Ab-MRI protocol 1 or 2); (2) all acquired MRI sequences (standard protocol); and (3) a combination of an Ab-MRI protocol (1 or 2) and CE-CT. Diagnostic performance was then statistically analyzed.

RESULTS

A total of 380 Lesions were analyzed, including 195 metastases (51.4%). Results from the two Ab-MRI protocols were similar. The sensitivity, specificity, and positive and negative predictive values from Ab-MRI were non-inferior to those from standard MRI (P > 0.05), while those from the combination of Ab-MRI protocol and CE-CT tended to be higher than those from Ab-MRI alone, although the difference was not significant (P > 0.05), and were quite similar to those from standard MRI (P > 0.05).

CONCLUSION

The diagnostic performances of two Ab-MRI protocols were non-inferior to that of the standard protocol. Combining Ab-MRI with CE-CT provided better diagnostic performance than Ab-MRI alone.

Non-hypervascular hepatobiliary phase hypointense lesions detected in patients with hepatocellular carcinoma: a post hoc analysis of SORAMIC trial to identify risk factors for progression

OBJECTIVES

To identify clinical and imaging parameters associated with progression of non-hypervascular hepatobiliary phase hypointense lesions during follow-up in patients who received treatment for hepatocellular carcinoma.

METHODS

A total of 67 patients with 106 lesions were identified after screening 538 patients who underwent gadoxetic acid-enhanced MRI within the SORAMIC trial. All patients were allocated to the trial treatment according to the trial scheme, and 61 of 67 patients received systemic treatment with sorafenib (either alone or combined with locoregional therapies) during the trial period. Follow-up images after treatment according to trial scheme were reviewed for subsequent hypervascularization or > 1 cm size increase. The correlation between progression and several imaging and clinical parameters was assessed using univariable and multivariable analyses.

RESULTS

On a median 178 (range, 48-1072) days follow-up period, progression was encountered in 18 (16.9%) lesions in 12 (17.9%) patients. In univariable analysis size > 12.6 mm (p = 0.070), ECOG-PS (p = 0.025), hypointensity at T1-weighted imaging (p = 0.028), hyperintensity at T2-weighted imaging (p < 0.001), hyperintensity at DWI images (p = 0.007), and cirrhosis (p = 0.065) were correlated with progression during follow-up. Hyperintensity at T2 images (p = 0.011) was an independent risk factor for progression in multivariable analysis, as well as cirrhosis (p = 0.033) and ECOG-PS (p = 0.030).

CONCLUSIONS

Non-hypervascular hepatobiliary phase hypointense lesions are associated with subsequent progression after treatment in patients with HCC. T2 hyperintensity, diffusion restriction, cirrhosis, and higher ECOG-PS could identify lesions with increased risk. These factors should be considered for further diagnostic evaluation or treatment of such lesions.

KEY POINTS

• Non-hypervascular hepatobiliary phase hypointense lesions have considerable risk of progression in patients with hepatocellular carcinoma receiving treatment. • T2 hyperintensity, cirrhosis, ECOG-PS, and hyperintensity at DWI are associated with increased risk of progression. • Non-hypervascular hepatobiliary phase hypointense lesions should be considered in the decision-making process of locoregional therapies, especially in the presence of these risk factors.

Compressed sensing for breath-hold high-resolution hepatobiliary phase imaging: image noise, artifact, biliary anatomy evaluation, and focal lesion detection in comparison with parallel imaging

PURPOSE

To assess image quality, performance for biliary anatomy diagnosis, and focal lesion detection rate of breath-hold high-resolution 3D T1-weighted hepatobiliary phase imaging using compressed sensing (CS HBP) compared to standard HBP using conventional parallel imaging.

METHODS

This retrospective study assessed consecutive 125 patients who underwent CS HBP and standard HBP between November 2019 and July 2020. Optimized resolution and scan time for CS HBP were 1 × 1.4 × 1 mm³ and 15 s, while those for standard HBP were 1.3 × 1.8 × 3 mm³ and 16 s. Two independent radiologists evaluated qualitative indices on the clarity of liver margin, visibility of the hepatic vessel and bile duct, image noise, and artifact on a 5-point scale. Biliary anatomy, confidence for biliary anatomy diagnosis, expected number of bile duct openings, and number of focal lesions were assessed. Wilcoxon signed-rank test, Pearson chi-square test, and sensitivity for focal lesion were used for statistical analysis. Intraclass correlation coefficient (ICC) and Cohen's kappa (κ) were used to determine inter-observer agreement.

RESULTS

CS HBP showed significantly better liver edge sharpness and bile duct visualization, but greater subjective image noise and non-respiratory artifacts compared to standard HBP. CS HBP showed higher number of concordantly assigned biliary anatomy across readers (86 vs. 80), indicating greater inter-observer agreement for biliary anatomy (κ, 0.67 vs. 0.45) and the number of bile duct openings (ICC, 0.860 vs. 0.579) with significantly higher diagnostic confidence (4.70-4.74 vs. 3.96-4.55; p = 0.002). Both readers identified more focal lesions in CS HBP than in standard HBP (88.2% and 84.5% vs. 66.3% and 73.4%).

CONCLUSION

Breath-hold high-resolution CS HBP was a feasible clinical sequence providing superior liver edge sharpness, bile duct visualization, and focal lesion detection rate compared to standard HBP despite higher noise and artifact. Due to improved spatial resolution, CS HBP yielded a higher inter-observer agreement and confidence for the biliary anatomy diagnosis.

Indeterminate liver lesions on gadoxetic acid-enhanced magnetic resonance imaging of the liver: Case-based radiologic-pathologic review

Different histopathological manifestations of focal liver lesions show varying common and uncommon imaging findings and some pathologies may show similar appearance despite of different histopathology. It is necessary to characterise focal liver lesions accurately as not only benign and malignant lesions are managed differently, but also certain benign lesions have differing management. These lesions are increasingly being detected due to rapid growth of use of cross-sectional imaging as well as improvement in image quality and new imaging techniques. Contrast enhanced magnetic resonance imaging (MRI) is considered the gold standard technique in characterising focal liver lesions. Addition of gadoxetic acid has been shown to significantly increase diagnostic accuracy in the detection and characterization of liver abnormalities. Classic imaging characteristics of common liver lesions, including their behaviour on gadoxetic acid enhanced MRI, have been described in literature over recent years. It is important to be familiar with the typical aspects of these lesions as well as know the uncommon and overlapping imaging features to reach an accurate diagnosis. In this article, we will review the well-described characteristic imaging findings of common and rare focal liver lesions and present several challenging cases encountered in the clinical setting, namely hepatocellular adenoma, focal nodular hyperplasia, hepatic angiomyolipoma, hepatocellular carcinoma, intrahepatic cholangiocarcinoma, neuroendocrine tumours as well as a pleomorphic liposarcoma of the liver.

Rim enhancement on hepatobiliary phase of pre-treatment 3.0 T MRI: A potential marker for early chemotherapy response in colorectal liver metastases treated with XELOX

PURPOSE

To assess the value of the enhanced features on the hepatobiliary phase (HBP) of pre-treatment Gd-EOB-DTPA MRI in evaluating response to chemotherapy in colorectal liver metastases (CRLMs).

METHODS

We retrospectively studied 65 patients with CRLMs who underwent Gd-EOB-DTPA enhanced MRI before chemotherapy from October 2015 to November 2017. The diagnosis of liver metastasis was established on the basis of imaging findings. Two radiologists evaluated the size, contrast-enhanced (CE) patterns of the maximum lesion on the HBP. According to the different CE patterns, we quantified area signal intensity (SI) by applying SI ratio (such as SI_center/outer and SI_rim/center). All of the above parameters were analyzed in terms of chemotherapy response.

RESULTS

Rim enhancement on the HBP was more frequent in the responding group of 28 patients (72%) than in the non-responding group of eight patients (31%). Additionally, there was a significant association between chemotherapy response and quantitative parameters: including diameter (P = 0.04), SI_center/outer (P = 0.047) and SI_rim/center (P = 0.012). The HBP CE pattern (P = 0.007) and SI_center/outer (P = 0.022) were independent factors for chemotherapy response. The areas under the curve (AUCs) of the above-mentioned parameters were significant associated with response to chemotherapy, in which diameter, HBP CE patterns, SI_center/outer, and SI_rim/center were 0.638, 0.706, 0.712, and 0.673, respectively. Moreover, the combination of these parameters obtained the largest AUC of 0.821.

CONCLUSION

The CE patterns, in particular with rim enhancement, and SI ratio parameters on the HBP are useful indicators for early evaluation of therapeutic response after chemotherapy in patients with CRLMs.

The value of hepatobiliary phase in EOB-MRI in predicting hypervascularization outcome of non-hypervascular hypointense lesions in high-risk patients for hepatocellular carcinoma

PURPOSE

To estimate the role of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced MRI (EOB-MRI) in predicting hypervascularization outcome of non-hypervascular hypointense hepatic lesions in high-risk patients for hepatocellular carcinoma (HCC).

METHODS

Under the premise of non-hyperenhance in arterial phase (AP) and hypointensity in hepatobiliary phase (HBP) of EOB-MRI, 29 fresh lesions from 22 patients with chronic viral hepatitis (median (range) age: 69(57-82) years) were prospectively enrolled. During continuously followed-up by EOB-MRI, lesional vascularity in AP, the signal intensity (SI) ratios of lesions-to-parenchyma in HBP images (post-contrast ratio) and adjusted enhancement with reference of unenhanced images (EOB enhancement ratio) were examined.

RESULTS

After 644 (220-2912) days of follow-up, 20 lesions changed into hyperenhancement in AP of EOB-MRI (hypervascularized group), while nine remained non-hyperenhanced (maintained non-hypervascular group). There is no statistical difference of post-contrast ratio at the initial detection. The post-contrast ratios in hypervascularized group were different between each follow-up time point when followed-up ≥ three (P < 0.01) and four (P < 0.05) times, and exposed a linear downward trend with time. Between the hypervascularized and maintained non-hypervascular groups, there were significant differences in the post-contrast ratio at endpoint for three-times' follow-up (P < 0.001); and at the second (P = 0.037), third follow-up time points (P = 0.005), endpoint (P = 0.005) for four-times' follow-up. EOB enhancement ratio showed inter-group difference only at endpoint for three-times' follow-up (P = 0.008).

CONCLUSION

For non-hypervascular, HBP hypointense hepatic lesions, decreasing trend of SI in HBP may early predict unfavorable hypervascularized outcome.

Gadoxetate disodium-enhanced MRI: Assessment of arterial phase artifacts and hepatobiliary uptake in a large series

PURPOSE

To report the quality of gadoxetate disodium MRI in a large series by assessing the prevalence of: 1) arterial phase (AP) artifacts and its predictive factors, 2) decreased hepatic contrast uptake during the hepatobiliary phase (HBP).

METHODS

This retrospective single center study included 851 patients (M/F:537/314, mean age: 63y) with gadoxetate disodium MRI. The MRI protocol included unenhanced, dual arterial [early and late arterial phases (AP)], portal venous, transitional and hepatobiliary phases. Three radiologists graded dynamic images using a 5-scale score (1: no motion, 5: severe, nondiagnostic) for assessment of transient severe motion (TSM, defined as a score ≥4 during at least one AP with a score ≤3 during other phases). HBP uptake was assessed using a 3-scale score (based on portal vein/hepatic signal). The association between demographic, clinical and acquisition parameters with TSM was tested in uni- and multivariate logistic regression.

RESULTS

TSM was observed in 103/851 patients (12.1 %): 83 (9.8 %) in one AP and 20 (2.3 %) in both APs. A score of 5 (nondiagnostic) was assigned in 7 patients in one AP (0.8 %) and none in both. Presence of TSM was significantly associated with age (p = 0.002) and liver disease (p = 0.033) in univariate but not in multivariate analysis (p > 0.05). No association was found between acquisition parameters and TSM occurrence. Limited or severely limited HBP contrast uptake was observed in 87 patients (10.2 %), and TSM was never associated with severely limited HBP contrast uptake.

CONCLUSION

TSM was present in approximately 12 % of gadoxetate disodium MRIs, rarely on both APs (2.3 %), and was poorly predicted. TSM was never associated with severely limited HBP contrast uptake.

The imaging findings of Peliosis hepatis on gadoxetic acid enhanced MRI

Peliosis hepatis involves multiple blood-filled cystic spaces in the hepatic parenchyma. Using conventional imaging, distinguishing PH from other malignancies can be difficult. The findings of Peliosis hepatis on gadoxetic acid (Gd-EOB) enhanced magnetic resonance imaging are not well reported. Therefore, we report the imaging features of pathologically proven PH. On the hepatobiliary phase of Gd-EOB magnetic resonance imaging, most lesions showed unenhanced areas, but some lesions showed central enhancement “halo sign.”

Hepatobiliary phase hypointensity predicts progression to hepatocellular carcinoma for intermediate-high risk observations, but not time to progression

PURPOSE

To determine whether hepatobiliary phase hypointensity, enhancing "capsule" and size provide prognostic information regarding the risk of progression to hepatocellular carcinoma (HCC), as well as the time to progression, of intermediate to high risk observations ≥ 10 mm with arterial phase hyperenhancement (APHE).

METHOD

This retrospective dual-institution study included 160 LR-3 and 26 LR-4 observations measuring more than 10 mm and having APHE in 136 patients (mean age [SD], 57 [11] years old). A composite reference standard of pathologic analysis and imaging follow-up was used. The prognostic performance of hepatobiliary phase hypointensity, enhancing "capsule" and size (cut-off: 20 mm) for the prediction of probability of progression to HCC and median time to progression to HCC was assessed and compared by means of Log-rank test, Cox-regression and Kaplan-Meier curves.

RESULTS

110 (59%) of 186 of observations progressed to HCC, 29.1% (32) progressed within 6 months, 60% (66) within 1 year and 84.5% (93) within 2 years. Hepatobiliary phase hypointensity was a significant predictor of progression to HCC (p < 0.0001, odds ratio: 20.62) but not of time to progression (p = 0.17). Median time to progression to HCC was 284 days [IQR: 266-363] and was shorter - though not significantly - for observations with enhancing "capsule" (118 days vs 301 days; p = 0.19).

CONCLUSIONS

Hepatobiliary phase hypointensity is an independent predictor of progression to HCC in intermediate to high risk APHE observations ≥ 10 mm.

Evaluation of hepatocellular carcinoma ablative margins using fused pre- and post-ablation hepatobiliary phase images

PURPOSE

To retrospectively evaluate the utility of fusion images of pre- and post-ablation hepatobiliary phase (HBP) series to assess the ablation margins after radiofrequency ablation (RFA) of hepatocellular carcinomas (HCCs). Additionally, to identify factors indicative of an adequate ablation margin and predictors of local tumor progression (LTP).

METHODS

Fifty-nine HCCs in 29 patients were treated by RFA and followed-up for > 1 year (mean 37.9 months). Fusion images of pre- and post-ablation HBP series were created using a non-rigid registration and manual correlation. The ablation margin appearance was classified as ablation margin + (ablation margin completely surrounding the tumor), ablation margin-zero (a partially discontinuous ablation margin without protrusion of HCC), ablation margin-(a partially discontinuous ablation margin with protrusion of HCC), and indeterminate (index tumor was not visible). The minimal ablation margin was measured, and clinical factors were examined to identify other risk factors for LTP.

RESULTS

LTP was observed at follow-up in 12 tumors. The mean minimal ablation margin was 3.6 mm. Multivariate analysis revealed that the ablation margin status was the only significant factor (p = 0.028). The cumulative LTP rates (3.3%, 3.3%, and 3.3% at 1, 2, and 3 years, respectively) in 30 ablation margin + nodules were significantly lower (p = 0.006) than those (20.0%, 28.0%, and 32.2% at 1, 2, and 3 years, respectively) in 25 ablation margin-zero nodules.

CONCLUSIONS

Fusion images enable an early assessment of the ablation efficacy in the majority of HCCs. The ablation margin status is a significant factor for LTP.

Hepatobiliary phase liver MR imaging findings after Oxaliplatin-based chemotherapy in cancer patients

OBJECTIVE

To describe Gd-EOB-DTPA-enhanced liver MR imaging findings in colon and rectal cancer patients who received Oxaliplatin.

CONCLUSION

Spectrum of hepatobiliary phase imaging findings include diffuse heterogeneous dysfunction, macronodular and micronodular FNH-like lesions, and coexistence of periportal increased liver function with FNH-like lesions. Differentiation of these benign lesions from metastasis is crucial to avoid biopsy in patients with colorectal cancers and may allow better understanding of sinusoidal obstruction syndrome pathophysiology and regenerative response of liver.

Optimization of hepatobiliary phase delay time of Gd-EOB-DTPA-enhanced magnetic resonance imaging for identification of hepatocellular carcinoma in patients with cirrhosis of different degrees of severity

AIM

To optimize the hepatobiliary phase delay time (HBP-DT) of Gd-EOB-DTPA-enhanced magnetic resonance imaging (GED-MRI) for more efficient identification of hepatocellular carcinoma (HCC) occurring in different degrees of cirrhosis assessed by Child-Pugh (CP) score.

METHODS

The liver parenchyma signal intensity (LPSI), the liver parenchyma (LP)/HCC signal ratios, and the visibility of HCC at HBP-DT of 5, 10, 15, 20, and 25 min (i.e., DT-5, DT-10, DT-15, DT-20, and DT-25 ) after injection of Gd-EOB-DTPA were collected and analyzed in 73 patients with cirrhosis of different degrees of severity (including 42 patients suffering from HCC) and 18 healthy adult controls.

RESULTS

The LPSI increased with HBP-DT more significantly in the healthy group than in the cirrhosis group (F = 17.361, P < 0.001). The LP/HCC signal ratios had a significant difference (F = 12.453, P < 0.001) among various HBP-DT points, as well as between CP-A and CP-B/C subgroups (F = 9.761, P < 0.001). The constituent ratios of HCC foci identified as obvious hypointensity (+++), moderate hypointensity (++), and mild hypointensity or isointensity (+/-) kept stable from DT-10 to DT-25: 90.6%, 9.4%, and 0.0% in the CP-A subgroup; 50.0%, 50.0%, and 0.0% in the CP-B subgroup; and 0.0%, 0.0%, and 100.0% in the CP-C subgroup, respectively.

CONCLUSION

The severity of liver cirrhosis has significant negative influence on the HCC visualization by GED-MRI. DT-10 is more efficient and practical than other HBP-DT points to identify most of HCC foci emerging in CP-A cirrhosis, as well as in CP-B cirrhosis; but an HBP-DT of 15 min or longer seems more appropriate than DT-10 for visualization of HCC in patients with CP-C cirrhosis.

Efficacy comparison of multi-phase CT and hepatotropic contrast-enhanced MRI in the differential diagnosis of focal nodular hyperplasia: a prospective cohort study

Background

Different clinical behaviour influences the importance of differentiating focal nodular hyperplasia (FNH) from other focal liver lesions (FLLs). The aim of this study was to compare the efficacy of contrast-enhanced CT and MRI in the diagnosis of FNH.

Methods

157 patients with equivocal FLLs detected in ultrasonography subsequently underwent multi-phase CT and MRI with the use of hepatotropic contrast agent (Gd-BOPTA) in a 1.5 T scanner. Examinations were evaluated by three independent readers. Diagnostic efficacy of different radiological signs of FNH in both CT and MRI was compared and AFROC analysis was performed.

Results

4 hepatocellular adenomas, 95 hepatocellular carcinomas, 98 hemangiomas, 138 metastases and 45 FNHs were diagnosed. In both CT and MRI the radiological sign of the highest accuracy was the presence of the central scar within FNH (0.93 and 0.96 relatively). The sum of two radiological signs in MRI: homogeneous enhancement in hepatic arterial phase (HAP) and enhancing lesion in hepatobiliary phase (HBP) was characterized with high values of sensitivity (0.89), specificity (0.97), PPV (0.82), NPV (0.98) and accuracy (0.96). After inclusion of clinical data into analysis the best discriminating feature in MRI was the presence of enhancing lesion in HBP in patients without cirrhosis. In this regard, efficacy parameters increased to 1.00, 0.99, 0.94, 1.00 and 0.99 accordingly. The area under the curve in AFROC analysis of MRI performance was significantly larger than of CT (p = 0.0145).

Conclusion

Gd-BOPTA-enhanced MRI is a more effective method in the differential diagnosis of FNH than multi-phase CT.

Electronic supplementary material

The online version of this article (10.1186/s12876-017-0719-1) contains supplementary material, which is available to authorized users.

Magnetic resonance findings of hepatic epithelioid hemangioendothelioma: emphasis on hepatobiliary phase using Gd-EOB-DTPA

PURPOSE

To examine the characteristic features of hepatic epithelioid hemangioendothelioma (HEH) on magnetic resonance imaging (MRI) using Gd-EOB-DTPA.

MATERIAL AND METHODS

Twelve patients (mean age, 50 years; male:female = 6:6) who were pathologically confirmed to have HEH in two tertiary institutions were retrospectively investigated. For qualitative analysis, the MRI features of HEH including core pattern were characterized, and lesions were divided into core and non-core groups. For quantitative analysis, standardized mean signal intensities (SI_st) measured at the tumor center, periphery, and liver parenchyma were plotted against the dynamic phases. Differences in SI_st between the core and non-core group were calculated for the tumor center and periphery. We also examined the radiologic and pathologic correlation for cases in which surgical resection was performed.

RESULTS

Forty-seven nodules in 12 patients were analyzed. The mean size of the lesions was 2.9 ± 1.0 cm. In the per-lesion analysis, ring-like arterial enhancement (74%) on arterial phase was the most frequent feature, followed by core pattern (51%), and hyperintense rim on T1-weighted imaging (43%). In the per-patient analysis, capsular retraction (75%) was the most common sign. The percentage of patients with core pattern was 58%. In the core group, the SI_st of the center showed slow enhancement starting from the transitional phase, resulting in divergence between the two graphs throughout the entire dynamic study (p < 0.05). Pathologically, the lesion center consisted of reduced cellularity with myxohyaline stroma and necrosis.

CONCLUSION

Core pattern can be considered a new diagnostic sign of HEH.

Comparison of 10- and 20-min hepatobiliary phase images on Gd-EOB-DTPA-enhanced MRI T1 mapping for liver function assessment in clinic

PURPOSE

To compare hepatobiliary phase (HBP) images obtained 10 and 20 min after Gd-EOB-DTPA-enhanced MRI for liver function assessment in clinic on 3.0 T MR imaging.

METHODS

103 patients were separated into four groups: 38 patients for the normal liver function (NLF) group, 33 patients for the liver cirrhosis with Child-Pugh A (LCA) group, 21 patients for the liver cirrhosis with Child-Pugh B group, and 11 patients for a liver cirrhosis with Child-Pugh C group. T1 relaxation times (T1rt) were measured on T1 mapping and reduction rates of T1rt (rrT1rt) were calculated. HBP images were obtained at the 10- and 20-min mark after Gd-EOB-DTPA enhancement.

RESULTS

T1rt on pre-enhancement imaging showed no significant difference (p > 0.05) among all four groups. T1rt for both the 10-min HBP and the 20-min HBP showed a significant difference (p < 0.05) among all groups, but showed no significant difference (p > 0.05) between the NLF group and the LCA group. T1rt and rrT1rt showed no significant difference (p > 0.05) between 10-min HBP and 20-min HBP among all groups. The ROC analysis on 10-min HBP and 20-min HBP showed a lower diagnostic performance between NLF group and LCA group (AUC from 0.532 to 0.582), but high diagnostic performance (AUC from 0.788 to 1.000) among others group.

CONCLUSIONS

In comparing 10-min HBP and 20-min HBP T1 mapping after Gd-EOB-DTPA enhancement, our results suggest that 10-min HBP T1 mapping is a feasible option for quantitatively assessing liver function.

Does hepatobiliary phase sequence qualitatively outperform unenhanced T1-weighted imaging in assessment of the ablation margin 24 hours after thermal ablation of hepatocellular carcinomas?

PURPOSE

To retrospectively determine whether hepatobiliary phase (HBP) sequence outperforms unenhanced T1-weighted imaging (uT1wI) in distinguishing the ablation margin (AM) from hepatocellular carcinoma (HCC) 24 h after thermoablation.

MATERIAL AND METHODS

Ninety-one patients [mean age, 65.7 years; 68 M/23F] with 138 HCCs (>6 months follow-up) underwent pre- and postablation gadoxetate disodium-enhanced MRI. AM showed a hyperintense middle zone (MZ) surrounding central hypo- or hyperintense HCCs on uT1wI, and an intermediate-intense MZ encompassing central hypo- or hyperintense HCCs during HBP. The visible AM was defined as persistent MZ around HCCs, which were demarcated from MZ, or peripherally band encompassing MZ, which were not demarcated from HCC. The indefinite AM was defined as no demarcating HCCs from MZ. The ability to distinguish AM from HCC was classified as visible or indefinite on axial (ax)-uT1wI, ax-HBP, coronal (cor)-HBP, and combined all images. To investigate the AM visibility during HBP, significance of differences upon comparison of ax-uT1wI with combined images was analyzed. Preablation liver-tumor contrast ratio (LTCR) on ax-uT1wI and ax-HBP sequence is compared between the visible and indefinite AM.

RESULTS

The McNemar test demonstrated a significant increase (p < 0.05) in visible AM from ax-uT1wI (60), to ax-HBP (70), cor-HBP (79), and combined images (83). TLCR with visible AM was significantly higher than that with indefinite AM on ax-uT1wI (0.4 vs. 0.2, p = 0.001) and ax-HBP sequence (0.9 vs. 0.6, p = 0.004).

CONCLUSIONS

HBP sequence might have higher feasibility to distinguish AM from tumor than ax-uT1wI. The TLCR value in visible AM was higher than that in indefinite AM on both ax-uT1wI and ax-HBP sequences.

Efficacy of the projection onto convex sets (POCS) algorithm at Gd-EOB-DTPA-enhanced hepatobiliary-phase hepatic MRI

PURPOSE

To investigate the efficacy of the projection onto convex sets (POCS) algorithm at Gd-EOB-DTPA-enhanced hepatobiliary-phase MRI.

METHODS

In phantom study, we scanned a phantom and obtained images by conventional means (P1 images), by partial-Fourier image reconstruction (PF, P2 images) and by PF with the POCS algorithm (P3 images). Then we acquired and compared subtraction images (P2-P1 images and P3-P1 images). In clinical study, 55 consecutive patients underwent Gd-EOB-DTPA (EOB)-enhanced 3D hepatobiliary-phase MRI on a 1.5T scanner. Images were obtained using conventional method (C1 images), PF (C2 images), and PF with POCS (C3 images). The acquisition time was 17-, 14-, and 14 s for protocols C1, C2 and C3, respectively. Two radiologists assigned grades for hepatic vessel sharpness and we compared the visual grading among the 3 protocols. And one radiologist compared signal-to-noise-ratio (SNR) of the hepatic parenchyma.

RESULTS

In phantom study, there was no difference in signal intensity on a peripheral phantom column on P3-P1 images. In clinical study, there was no significant difference between C1 and C3 images (2.62 ± 0.49 vs. 2.58 ± 0.49, p = 0.70) in the score assigned for vessel sharpness nor in SNR (13.3 ± 2.67 vs. 13.1 ± 2.51, p = 0.18).

CONCLUSION

The POCS algorithm makes it possible to reduce the scan time of hepatobiliary phase (from 17 to 14 s) without reducing SNR and without increasing artifacts.

Is there an added value of a hepatobiliary phase with gadoxetate disodium following conventional MRI with an extracellular gadolinium agent in a single imaging session for detection of primary hepatic malignancies?

PURPOSE

To determine added value of hepatobiliary phase (HBP) using gadoxetate disodium compared to MRI with extracellular gadolinium-based contrast agent (GBCA) for detection of primary hepatic malignancies in a single imaging session.

MATERIALS AND METHODS

IRB approved this HIPAA compliant retrospective study. Within 90 days of resection or liver transplant, thirty patients underwent MRI with extracellular GBCA followed by separate injection of gadoxetate for HBP. Two sets of images were reviewed: Set #1-unenhanced and enhanced images with an extracellular GBCA and set #2-with addition of HBP. Data were analyzed in two groups, cases with hepatocellular carcinoma (HCC) only and cases with either HCC and/or cholangiocarcinoma. Observer diagnostic accuracy (Az), sensitivity, and specificity were calculated.

RESULTS

14/30 subjects had HCC (46%, CI 28-66%), 2/30 (2%, CI 1-22%) cholangiocarcinoma, and 14/30 (46%, CI 28-66%) no malignancy. There was no significant change in A z value with addition of gadoxetate in the detection of HCC (range 0.84-0.97 set #1 and 0.85-0.97 set #2, p > 0.05). Sensitivity and specificity showed no significant differences (p > 0.05) between the image sets for all readers. When stratified by lesion size, there was no significant difference in accuracy, sensitivity, or specificity for any reader (p > 0.05).

CONCLUSION

When compared to extracellular GBCA, gadoxetate HBP imaging does not result in a significant difference in accuracy or sensitivity in diagnosis of HCC or cholangiocarcinoma and may result in a decrease in specificity.

Usefulness of breath-hold inversion recovery-prepared T1-weighted two-dimensional gradient echo sequence for detection of hepatocellular carcinoma in Gd-EOB-DTPA-enhanced MR imaging

The aim is to evaluate the diagnostic performance and the added value of breath-hold inversion recovery-prepared T1-weighted two-dimensional gradient echo (IR-2D-GRE) sequence for detection of hepatocellular carcinoma (HCC) in patients with insufficient liver parenchymal enhancement during the hepatobiliary phase (HBP) of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI). Seventeen patients with a quantitative liver-to-spleen contrast ratio of ≤1.5 on HBP images and 36 HCCs were included. Liver-to-lesion contrast ratios on HBP images obtained with IR-2D-GRE sequence were significantly higher than those with three-dimensional gradient echo sequence. The addition of IR-2D-GRE sequence during HBP of Gd-EOB-DTPA-enhanced MRI yielded higher diagnostic accuracy and improved sensitivity.

Clinical value of gadoxetic acid-enhanced magnetic resonance imaging in surgery for hepatocellular carcinoma - with a special emphasis on early hepatocellular carcinoma

Gadoxetic acid- or gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) achieves excellent lesion detection and characterization for both hypervascular hepatocellular carcinoma (HCC) in arterial phase imaging and hypovascular early HCC (small well-differentiated HCC of the vaguely nodular type) in hepatobiliary phase imaging, and has become an indispensable imaging modality in the treatment of HCC. Early HCCs have been detected more frequently since the introduction of EOB-MRI into daily clinical practice. Early HCC is known to progress to conventional hypervascular HCC, and many risk factors have been identified for the hypervascularization of early HCC including the diameter of the tumor, presence of fat, and imaging findings of EOB-MRI. The rate of the development of hypervascular HCC was previously reported to be high in patients with chronic liver disease and early HCC. The presence of early HCC is regarded as a predictor for the recurrence of HCC following hepatic resection. On the other hand, although early HCC itself is currently not regarded as a target lesion for hepatic resection, early HCC at high risk of hypervascularity needs to be treated by local ablation therapy. If concomitant early HCC with progressed HCC is at high risk of hypervascularization and the functional liver reserve of a patient is sufficient, its simultaneous treatment at the time of hepatic resection for progressed HCC is recommended. Further studies on larger numbers of patients are needed before this strategy is adopted.

MR liver imaging with Gd-EOB-DTPA: The need for different delay times of the hepatobiliary phase in patients with different liver function

PURPOSE

To determine the optimal hepatobiliary delay time after Gd-EOB-DTPA injection for lesion characterization in cirrhosis patients with different liver function.

MATERIALS AND METHODS

Ninety consecutive patients with liver cirrhosis who underwent Gd-EOB-DTPA-enhanced MRI for the evaluation of known or suspected focal liver lesions were enrolled in this retrospective study. The patients were divided into Child-Pugh A, B and C groups depending on their liver function through the Child-Pugh classification. Hepatobiliary phase images obtained at 5, 10, 15, and 20min were assessed in each group by the following items: parenchymal enhancement, contrast agent excretion into the bile ducts and ureter, and contrast- and signal-to-noise ratios for lesions.

RESULTS

In the Child-Pugh A group, parenchymal enhancement increased significantly from 5min to 15min (P<0.05), and stabilized at 20min (P=0.22). However, there was no significant difference in parenchymal enhancement among all of the hepatobiliary phases in the Child-Pugh B and C groups. The biliary contrast agent excretion was first observed before 20min in all of the patients in the Child-Pugh A group, at 20min in 4 patients (25%) in the Child-Pugh B group, and after 20min in 11 patients (78.6%) in the Child-Pugh C group. The numbers of patients whose urethral contrast agent excretion was first observed at 5min in the Child-Pugh A, B and C groups were 38 (63.3%), 12 (75.0%) and 11 (78.6%), respectively. The CNR of the lesions increased significantly (P<0.05), up to 15min after enhancement without a further increase at 20min in the Child-Pugh A group; however, no significant change was found from 5min to 20min in the Child-Pugh B and C groups. For the SNR of lesions, there was no significant difference at 5, 10, 15 and 20min in all of the groups.

CONCLUSIONS

A delay time of 15min for the hepatobiliary phase was sufficient for patients with mild liver dysfunction who were classified as Child-Pugh A. Nevertheless, for the patients with moderate or severe liver dysfunction who were classified as Child-Pugh B or C, a delay time longer than 5min is meaningless for lesion characterization.

Liver-specific gadoxetic acid-enhanced magnetic resonance for focal lesion evaluation

Gadolinium-enhanced magnetic resonance for the evaluation of hepatic lesions is increasingly being used in clinical practice, especially in patients with suspicious focal lesions, whether benign or malignant. In regard to hepatocellular carcinoma, the diagnostic performance of magnetic resonance through the «conventional» protocols and multi-detector computerized tomography consisting of multiphase evaluation with intravenous contrast, largely depends on the size of the lesion. They are more reliable in lesions>2cm. However, in lesions measuring 1-2cm, establishing the definitive diagnosis is a real challenge, with sensitivity values of 45-65%, but generally with excellent specificity (>95%). Furthermore, if the lesion has a diameter<1cm, diagnosis is usually unreliable. In these last 2 settings, the complementary use of liver-specific contrast agents can be advantageous. The aim of our article was to review the current evidence on the usefulness of this new non-invasive diagnostic method in hepatic lesions.

Visualization of liver uptake function using the uptake contrast-enhanced ratio in hepatobiliary phase imaging

PURPOSE

To visualize liver uptake function using the uptake contrast-enhanced ratio in hepatobiliary phase (uptake CERH) magnetic resonance imaging.

MATERIALS AND METHODS

Thirty-seven patients with hepatocellular carcinoma (HCC) and 23 with metastatic liver cancer were evaluated. Hepatobiliary phase images were acquired 20min after an intravenous bolus injection of gadoxetic acid disodium. We assumed that the contrast-enhanced ratio in the hepatobiliary phase (CERH) in the spleen was similar to the contrast-enhanced ratio in the extracellular matrix (CEREM). The Uptake CERH value was defined as the percentage signal gain between the precontrast and hepatobiliary phase images (without CEREM). The Uptake CERH value measured the tumor-free liver parenchyma. The association of the uptake CERH value with the biochemical liver function test results, and hepatocellular density in the liver parenchyma was assessed. Correlations were examined using Pearson correlation coefficient and the Mann-Whitney test.

RESULTS

The uptake CERH value was correlated with albumin, bilirubin, indocyanine green retention rate at 15min, prothrombin activity(%), platelet count, and cellular density in the liver parenchyma (p<0.01).

CONCLUSIONS

Uptake CERH images are useful for visualizing liver uptake function.

Added value of hepatobiliary phase gadoxetic acid-enhanced MRI for diagnosing hepatocellular carcinoma in high-risk patients

AIM: To determine the added value of hepatobiliary phase (HBP) gadoxetic acid-enhanced magnetic resonance imaging (MRI) in evaluating hepatic nodules in high-risk patients.

METHODS: The institutional review board approved this retrospective study and waived the requirement for informed consent. This study included 100 patients at high risk for hepatocellular carcinoma (HCC) and 105 hepatic nodules that were larger than 1 cm. A blind review of two MR image sets was performed in a random order: set 1, unenhanced (T1- and T2-weighted) and dynamic images; and set 2, unenhanced, dynamic 20-min and HBP images. The diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were compared for the two image sets. Univariate and multivariate analyses were performed on the MR characteristics utilized to diagnose HCC.

RESULTS: A total of 105 hepatic nodules were identified in 100 patients. Fifty-nine nodules were confirmed to be HCC. The diameter of the 59 HCCs ranged from 1 to 12 cm (mean: 1.9 cm). The remaining 46 nodules were benign (28 were of hepatocyte origin, nine were hepatic cysts, seven were hemangiomas, one was chronic inflammation, and one was focal fat infiltration). The diagnostic accuracy significantly increased with the addition of HBP images, from 88.7% in set 1 to 95.5% in set 2 (P = 0.002). In set 1 vs set 2, the sensitivity and NPV increased from 79.7% to 93.2% and from 78.9% to 91.8%, respectively, whereas the specificity and PPV were not significantly different. The hypointensity on the HBP images was the most sensitive (93.2%), and typical arterial enhancement followed by washout was the most specific (97.8%). The multivariate analysis revealed that typical arterial enhancement followed by washout, hyperintensity on T2-weighted images, and hypointensity on HBP images were statistically significant MRI findings that could diagnose HCC (P < 0.05).

CONCLUSION: The addition of HBP gadoxetic acid-enhanced MRI statistically improved the diagnostic accuracy in HCCs larger than 1 cm. Typical arterial enhancement followed by washout and hypointensity on HBP images are useful for diagnosing HCC.